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Bubble sort
The bubble sort is clearly not know as the best sort algorithm, though it's easy to implement.
Compare two adjacent cells and swap the 2 values if first is greater than second, then move the bubble along the array. This way, smaller values will be moved up, like bubbles on water.
Let's start
- Memory: 0 array 0 0 0
- Cursor: after last array cell
- Input: any
Process
- note : we will go through the array from end to beginning, to make sure there is always enough space
- Set a continue loop flag to 1
- Memory : 0 0 array1 0 0 0 0 0 array2 0 loopFlag
- While loop flag is not null
- Reset loop flag
- Go to the end of array1
- While there are 2 cells
- Copy them
- Compare copies
- If 1st > 2nd
- moves 1st to beginning of array2
- set loopFlag to 1 (reset, then set to 1)
- otherwise move 2nd
- move array2 back after array1
- loop if needed
Code
>>>>>>+ set loop flag
[- loop: reset flag
<<[<]<<<<< go to end of array 1
<[ while there are at least 2 cells
[[->>>>+<<<<]>] move the 2 cells
>>[[-<<+<<+>>>>]>] copy and move back
<<<[->+<]<[->+<]>>[-<< swap the 2 values and then
+>>]+<<[->[->]>[<<[-]>>- compare them
>>]<<+<<]>[[-]<+>]>-<+< ** part 2 **
[->-< 2nd smaller than 1st: reset else flag
<<[->>>>>>+<<<<<<] move 1st value at beginning of array 2
>[-<+>] and move 2nd at end of array 1
>>>>>[>]>[-]+ set loop flag to 1
<<[<]<<<]>[- else 1st smaller then
<<[->>>>>+<<<<<] move 2nd value at beginning of array 2
>>] end if / else
<<<<] loop on new pair
>>>>>>>[[-<<<<<+>>>>>]>] move array2 back
>] loop if flag is set
<<<<<< go to original position one cell after array
Minified version
>>>>>>+[-<<[<]<<<<<<[[[->>>>+<<<<]>]>>[[-<<+<<+>>>>]>]<<<[->+<]<[->+<]>>[-<<+>>]
+<<[->[->]>[<<[-]>>->>]<<+<<]>[[-]<+>]>-<+<[->-<<<[->>>>>>+<<<<<<]>[-<+>]>>>>>[>
]>[-]+<<[<]<<<]>[-<<[->>>>>+<<<<<]>>]<<<<]>>>>>>>[[-<<<<<+>>>>>]>]>]<<<<<<
Final state
- Memory: 0 sorted array 0 0 0
- Cursor: after last array cell
- Input: unchanged
- Output: unchanged
Test program
This program reads chars from the input, then sort and print them.
>,[>,]
>>>>>>+[-<<[<]<<<<<<[[[->>>>+<<<<]>]>>[[-<<+<<+>>>>]>]<<<[->+<]<[->+<]>>[-<<+>>]
+<<[->[->]>[<<[-]>>->>]<<+<<]>[[-]<+>]>-<+<[->-<<<[->>>>>>+<<<<<<]>[-<+>]>>>>>[>
]>[-]+<<[<]<<<]>[-<<[->>>>>+<<<<<]>>]<<<<]>>>>>>>[[-<<<<<+>>>>>]>]>]<<<<<<
<[<]>[.>]
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